[PerfectSlayer]

What Does This Do

This PR adds a pull request size check to prevent large change sets and difficult code reviews.
It promotes split and stacked PRs instead, which are a very nice way to with review.
Coding agents now how to deal with them so it should not be an issue for both humans and agent authors.

Motivation

When change set is too big, it becomes very hard for reviewers to verify the content.
Additionally, the automatic agentic review only raise 3 to 5 errors. So for a change of 3k LOC, it's about only one feedback per 600 to 1000 LOC. Limit to 1k LOC would also bring more automatic review comments (about 1 comment per 200 LOC at most).

Additional Notes

Line moves, deletions, test code and resources (src/test), and version lock files do not count toward the change set size limit.
Over the last 6 months, 28 of the 1235 PRs merged into master would have been blocked.
And there is an exceptional tag: override pr size check label to unblock PR if needed.
The check will run first as a non blocking workflow for evaluation.

Contributor Checklist

• Format the title according to the contribution guidelines
• Assign the type: and (comp: or inst:) labels in addition to any other useful labels
• Avoid using close, fix, or any linking keywords when referencing an issue
  Use solves instead, and assign the PR milestone to the issue
• Update the CODEOWNERS file on source file addition, migration, or deletion
• Update public documentation with any new configuration flags or behaviors
• Once approved, use merge queue to merge the PR

Jira ticket: [PROJ-IDENT]

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-21T10:47:22.218621Z	893558f	PR opened
🔒 Security Review	✅ Completed 2026-10-21T10:48:01.370424Z	893558f	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 893558f10e

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[datadog-datadog-prod-us1-2]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 59.51% (-0.02%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 255b438 | Docs | Give us feedback!}

[datadog-datadog-prod-us1-2]

The workflow executes PR-controlled shell code with OIDC access capable of obtaining repository-wide issue and pull-request write permissions. Its comment lookup can also target contributor comments instead of the bot’s warning.

_{Open Bits AI session}

_{🤖 Bits Code Review · Commit 893558f}

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	14.01 s	13.98 s	[-0.5%; +1.0%] (no difference)
startup:insecure-bank:tracing:Agent	12.93 s	12.98 s	[-1.1%; +0.3%] (no difference)
startup:petclinic:appsec:Agent	17.20 s	17.00 s	[+0.3%; +2.1%] (maybe worse)
startup:petclinic:iast:Agent	17.05 s	17.16 s	[-1.5%; +0.2%] (no difference)
startup:petclinic:profiling:Agent	16.18 s	16.72 s	[-7.5%; +1.0%] (no difference)
startup:petclinic:sca:Agent	17.12 s	17.08 s	[-0.7%; +1.2%] (no difference)
startup:petclinic:tracing:Agent	16.29 s	16.23 s	[-0.6%; +1.3%] (no difference)

Commit: 255b438d · CI Pipeline · Benchmarking Platform UI

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Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

[sarahchen6]

Let's try it out 👍